Apparatus for separating flowable constituents from a substance mixture

ABSTRACT

The invention relates to an apparatus for separating the flowable constituents from a mixture of flowable and non-flowable constituents particularly for the preparation of foodstuffs, the apparatus includes a driven perforated drum having a perforated circumferential surface, a pressure belt enclosing part of the circumference thereof and pressable onto the same by at least one pressure roller, as well as a supply mechanism for supplying the product to be treated into an entry wedge formed between the perforated drum and the pressure belt.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus for separating the flowableconstituents from a mixture of flowable and non-flowable constituentsparticularly for the preparation of foodstuffs, the apparatus comprisinga driven perforated drum having a perforated circumferential surface, apressure belt enclosing part of the circumference thereof and pressableonto the same by means of at least one pressure roller, as well as asupply mechanism for supplying the product to be treated into an entrywedge formed between the perforated drum and the pressure belt.

2. Prior Art

The basic concept of such apparatus is that of a separator type, asdisclosed, for example, in East German Pat. No. 96 155. The substancemixture introduced into such an apparatus and formed from flowable andnon-flowable constituents is, after feeding and drawing into the wedgebetween the perforated drum and the pressure belt first pressed onto theperforated drum as a result of the radial pressure derived from theaxial tension of the belt and in this way is supplied to the actualpressing point. This is formed by a pressure roller supporting thepressure belt and settable against the perforated drum, so that apressure gap can be adjusted, in which, as a result of the elasticity ofthe pressure belt, the outflow of the flowable constituents through theperforations of the perforated drum into the interior thereof iseffected through quasi-hydraulic pressure. In contrast thereto, thenon-flowable constituents pass through the pressure gap accompanied byelastic embedding in the pressure belt and are subsequently strippedfrom the outer circumference of the perforated drum, if they have notbeen dropped already after release through the pressure gap.

Such apparatuses permit, in an uncomplicated manner, the separation ofmeat from tissues, bones and skin, so that they are mainly used in theproduction of sausages. However, as a function of the working product,particularly in the case of meat portions mixed, for example, with bonefragments, it has been found that when a small proportion of suchfragments or other hard parts can, as a result of the particle sizethereof pass in unhindered manner through the openings of the perforateddrum. This also occurs in the case of longish particles, if they passinto the separator with a radial alignment with respect to theperforated drum.

Even in the case of an obvious use of such apparatuses for the unpackingand recovery of incorrectly packed flowable foods, such as cheese,butter, etc., accompanied by the simultaneous separation thereof fromthe packing material residues similar problems occur. These aremanifested by an inadequate degree of purity of the recovered material.The reason for this is that the openings act as a punching die withrespect to the pressure belt and the normally metallic, plastic or paperpackaging or separating films or foils, as a function of thecharacteristics of the material thereof are punched out at least oversingle openings, so that said parts are floated out together with theoutflowing material into the interior of the perforated drum. However,this phenomenon also occurs disadvantageously in the case of strongerfilms or foils, because, as a result of the pressure action, they areforced into the openings of the perforated drum, the packing materialmembranes formed over said openings at least partially bursting orsplitting. The resulting perforations in the foils admittedly do notinitially bring about a separation of foil particles, because the foils'tips forming at the perforation points with the flow of the outflowingfood material are merely drawn into the openings without tearing off.However, when the packing material residues have left the pressing zonesubsequently, then they remain in this state due to the positiveanchoring in the openings, as well as to the generally effectiveadhesive forces on the circumferential surface of the perforated drum,so that constrained stripping is necessary. The equipment provided tothis end comprises a stripping blade which scrapes over thecircumferential surface of the perforated drum. Part of the foils' tipsdrawn into the openings are sheared-off, so that during the nextrevolution they are floated into the interior of the perforated drumtogether with the freshly squeezed out food material and lead to thesoiling of the recovered material.

An apparatus disclosed in German Pat. No. 32 11 625 aims at eliminatingthis disadvantage. It is based on the idea that shearing is avoidableif, through the moving back of the material filling the openings in theperforated drum and which can be looked upon as a hydraulic medium,there is a floating back of the packing parts which have entered theopenings prior to stripping by means of the stripping blade. The highlyelastic inner roller provided for this purpose led to this effect, butthis has led to a deterioration in output and yield, so that thisapparatus has not become widely used for reasons of economy.

3. Objects of the Invention

It is therefore a major problem of the present invention to overcomethese disadvantages by suggesting an apparatus permitting a betterseparation of flowable and nonflowable constituents from a mixturethereof. It is a further object of the invention to provide an apparatuswhich, in particular, permits the recovery of incorrectly packed viscousmaterials. It is yet another object of the invention to propose suchapparatus which achieves a high output or yield and without impairingthe purity of the resulting product.

SUMMARY OF THE INVENTION

In an apparatus comprising a driven perforated drum having a perforatedcircumferential surface, a pressure belt enclosing part of thecircumference thereof and pressable onto the same by means of at leastone pressure roller, as well as a supply mechanism for supplying thetreatment product into an entry wedge formed between the perforated drumand the pressure belt, this problem is solved, according to the presentinvention, in that the circumferential surface of the perforated drumhas a non-perforated circumferential zone in its effective region.Advantageously, the supply mechanism should be positioned so as to bedirected towards at least the central area of the non-perforatedcircumferential zone. It is particularly expedient with regard to thethroughput if the perforated drum is designed such that thenon-perforated circumferential zone covers the central portion of theperforated drum, on either side of which central portion the perforatedmarginal zones will follow. It is favourable for the outflow of thematerial if the pressure belt covering the non-perforatedcircumferential zone and the perforated marginal zones has a thicknessdecreasing from the centre towards the edges. This effect can also beachieved if the effective region of the perforated drum is designed as adouble cone, whose largest diameter is provided in the centre of thenon-perforated circumferential zone.

When using the apparatus for the recovery of incorrectly packed viscousmaterials, it is advantageous if the circumferential surface of theperforated drum facing the pressure belt is, in the vicinity of itsnon-perforated circumferential zone, provided with grooves runningsubstantially parallel to the perforated drum axis and extending intothe perforated marginal zones, because in this way it can be ensuredthat no material film builds up on the circumferential surface of theperforated drum on which film the packing material would be able toslide in the vicinity of the perforated marginal zones. As a result, itis achieved that the packing material foils or films remain in theregion of the non-perforated circumferential zone, so that the risk ofpunching through and therefore impurification is prevented.

This effect can be improved further in that at least in the transitionregion between the non-perforated circumferential zone and theperforated marginal zones, radial grooves are provided, the depth of thegrooves perferably being deeper than that of the radial grooves.

BRIEF DESCRIPTION OF THE DRAWINGS

Other and further objects of the present invention will be apparent fromthe following description and claims and are illustrated in theaccompanying drawings, which by way of illustration schematically showpreferred embodiments of the present invention and the principlesthereof and what now are considered to be the best modes contemplatedfor applying these principles. Other embodiments of the inventionembodying the same or equivalent principles may be used and structuralchanges may be made as desired by those skilled in the art withoutdeparting from the present invention and the scope of the appendedclaims. In the drawings

FIG. 1 shows an overall view of the apparatus in an axonometricrepresentation with a supply mechanism in an exploded arrangement;

FIG. 2 shows a cross-section through the perforated drum along sectionline II;

FIG. 3 shows a cross-section corresponding to FIG. 2 with a modifiedpressure belt;

FIG. 4 shows a cross-section corresponding to FIG. 2 with a modifiedperforated drum; and

FIG. 5 shows a detail of the perforated drum in an axonometricrepresentation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In a not shown frame of a press-passing or mincing machine constructedin known per se manner, there are provided between not shown side wallsa perforated drum 1 having openings 4 passing through cylindrical zonesof its circumferential surface 2, a pressure roller 5 adjustable withrespect to its position relative to the circumferential surface 2, aswell as a deflection roller 6 and a tension roller 7. Whilst the latterare arranged as idler rollers, i.e. so as to revolve loosely, theperforated drum 1 and the pressure roller 5 are driven to rotate at anat least approximately equal circumferential speed. The rollers 5, 6 and7 carry a flexible pressure belt 8 revolving in playfree manner betweenthe side walls and which encloses the perforated drum 1 over part of itscircumference. The pressure belt 8 can be compressed to a fraction ofits thickness by the pressure roller 5, the belt's outer surface 9,which is designed with a good grip, e.g. by knurling, being held underthe pressure against the circumferential surface 2 of the perforateddrum 1. Downstream of the pressure roller 5, when seen in the rotationdirection of the perforated drum 1, there is positioned a strippingmechanism 10 with at least one stripping blade, which strippingmechanism is adjustable to the narrowest gap with respect to thecircumferential surface 2 of the perforated drum 1. Above an entry wedgeformed by the pressure belt 8 and the perforated drum 1, there isprovided a supply or feeding device 11, which allows the supply ofpressing material into a circumferential zone 12 arranged centrally andnot provided with openings 4.

The function of the apparatus is as follows:

The material to be treated or processed is introduced into the entrywedge between pressure belt 8 and perforated drum 1 by means of supplymechanism 11 and is drawn into the enclosing or looping area betweenperforated drum 1 and pressure belt 8 as a result of the revolution ofthese two parts. The material is pressurized initially by the radialpressure component resulting from the tension of the pressure belt 8.Due to the lack of perforations of the circumferential surface 2 in thecharging or supply region of the perforated drum 1, the material to betreated is shaped into a material band, whose flowable constituentsstart to flow in the direction of the only remaining way out, namelyalong the generatrixes (circumferential lines) of the perforated drum 1.Grooves 13, located, as shown in FIG. 5, in the region of thenon-perforated circumferential zone 12 of the perforated drum 1facilitates the outflow of the material into perforated marginal zones3, so that the building-up of a sliding film is avoided, because such afilm would lead to the risk of packing material films or foils passinginto the area of the perforated marginal zones 3, where it could bepunched over the openings 4 by the pressure belt 8. This risk is alsocounteracted by radial grooves 14, which bring about a positive adhesionbetween the packing foils and the perforated drum 1, without the outflowof squeezed out material being prevented due to the greater depth of thegrooves 13. Thus, while the clamping force acting between the perforateddrum 1 and the pressure belt 8 ensures that the solid particles of thematerial to be treated are held clamped and consequently secured, theflowable constituents flow towards the perforated marginal zones 3 and,at the latest on reaching the actual pressure zone in the region ofpressure roller 5, flow out through the openings 4 into the interior ofthe perforated drum 1.

To assist the outflow of the flowable constituents and simultaneously toretain the solid constituents, the pressure belt 8 can have a thicknesswhich decreases from the centre line to the marginal areas. The outersurface 9 of the pressure belt 8 coming into contact with the materialto be treated is preferably flat and the inner surface facing therollers 5, 6 and 7 is preferably roof-shaped. In this case, thecylindrical configuration of the pressure roller 5 is retained, whilstthe deflection roller 6 and the tension roller 7 are given acircumferential surface design adapted to the shape of the inner surfaceof the pressure belt 8. Therefore, a higher pressure zone forms in thecentral region of the pressure belt 8, which pressure decreases towardsthe marginal areas thereof.

The same effect is obtained if the perforated drum 1 is designed as adouble cone with maximum diameter in the middle of its working surface.

I claim:
 1. Apparatus for the processing of a material mixturecontaining flowable and non-flowable components, particularly in thepreparation of foodstuffs, by separating said flowable components fromsaid mixture, said apparatus comprisinga driven drum defining a apressure belt enclosing part of said circumferential surface and formingan entry wedge with said drum; at least one pressure roller positionedso as to press said belt onto said circumferential surface; supply meansfor supplying said mixture to be processed into said entry wedge formedbetween said drum and said pressure belt, said circumferential surfaceincludes at least one non-perforated circumferential zone passingcompletely around a circumference of said drum and at least oneperforated circumferential zone, axially adjacent said non-perforatedcircumferential zone and passing completely around said circumference ofsaid drum.
 2. Apparatus as claimed in claim 1, wherein said supply meansincludes means for feeding said mixture to at least an axially centralregion of said at least one non-perforated circumferential zone and forpreventing direct feeding of said mixture to at least one of saidperforated circumferential zones.
 3. Apparatus accordng to claim 2,wherein:said at least one non-perforated circumferential zone is axiallycentered in said drum; said at least one perforated circumferential zonebeing at least first and second perforated circumferential zones; saidfirst perforated circumferential zone being disposed adjacent a firstedge of said at least one non-perforated circumferential zone; and saidsecond perforated circumferential zone being disposed adjacent a secondopposed edge of said at least one non-perforated circumferential zone.4. Apparatus according to claim 1, wherein:said at least onenon-perforated circumferential zone is axially centered in said drum;said at least one perforated circumferential zone being at least firstand second perforated circumferential zones; said first perforatedcircumferential zone being disposed adjacent a first edge of said atleast one non-perforated circumferential zone; and said secondperforated circumferential zone being disposed adjacent a second opposededge of said at least one non-perforated circumferential zone. 5.Apparatus for the processing of a material mixture containing flowableand non-flowable components by separating said flowable components fromsaid mixture, said apparatus comprising:a driven drum defining acircumferential surface; a pressure belt enclosing part of saidcircumferential surface and forming an entry wedge with said drum; atleast one pressure roller positioned so as to press said belt onto saidcircumferential surface; and supply means for supplying said mixtureinto said entry wedge; at least one non-perforated circumferential zonein said circumferential surface; at least one perforated circumferentialzone in said circumferential surface; and said pressure belt has athickness decreasing from its center toward its edges.
 6. Apparatus asclaimed in claim 5 wherein said circumferential surface of said drum isprovided with grooves in the region of said at least one non-perforatedcircumferential zone, said grooves extending substantially parallel to alongitudinal axis of said drum, and into said at least one perforatedzone.
 7. Apparatus for the processing of a material mixture containingflowable and non-flowable components by separating said flowablecomponents from said mixture, said apparatus comprising:a driven drumdefining a circumferential surface; a pressure belt enclosing part ofsaid circumferential surface and forming an entry wedge with said drum;at least one pressure roller positioned so as to press said belt ontosaid circumferential surface; and supply means for supplying saidmixture into said entry wedge; at least one non-perforatedcircumferential zone in said circumferential surface; at least oneperforated circumferential zone in said circumferential surface; saidsupply means includes means for feeding said mixture to at least anaxially central region of said at least one non-perforatedcircumferential zone; said pressure belt has a thickness decreasing fromits center toward its edges.
 8. Apparatus for the processing of amaterial mixture containing flowable and non-flowable components byseparating said flowable components from said mixture, said apparatuscomprising:a driven drum defining a circumferential surface; a pressurebelt enclosing part of said circumferential surface and forming an entrywedge with said drum; at least one pressure roller positioned so as topress said belt onto said circumferential surface; and supply means forsupplying said mixture into said entry wedge; at least onenon-perforated circumferential zone in said circumferential surface; atleast one perforated circumferential zone in said circumferentialsurface; said at least one non-perforated circumferential zone isaxially centered in said drum; said at least one perforatedcircumferential zone being at least first and second perforatedcircumferential zones; said first perforated circumferential zone beingdisposed adjacent a first edge of said at least one non-perforatedcircumferential zone; and said second perforated circumferential zonebeing disposed adjacent a second opposed edge of said at least onenon-perforated circumferential zone; said pressure belt covering atleast one of said at least on non-perforated circumferential zone andsaid at least one perforated zone, has a thickness decreasing from anaxial center thereof toward its edges.
 9. Apparatus for the processingof a material mixture containing flowable and non-flowable components byseparating said flowable components from said mixture, said apparatuscomprising:a driven drum defining a circumferential surface; a pressurebelt enclosing part of said circumferential surface and forming an entrywedge with said drum; at least one pressure roller positioned so as topress said belt onto said circumferential surface; and supply means forsupplying said mixture into said entry wedge; at least onenon-perforated circumferential zone in said circumferential surface; atleast one perforated circumferential zone in said circumferentialsurface; and said drum has a shape of a double cone having a maximumdiameter in an axial centre of said at least one non-perforatedcircumferential zone.
 10. Apparatus as claimed in claim 9, wherein saidcircumferential surface of said drum is provided with grooves in theregion of said at least one non-perforated circumferential zone, saidgrooves extending substantially parallel to a longitudinal axis of saiddrum, and into said at least one perforated marginal zone.
 11. Apparatusfor the processing of a material mixture containing flowable andnon-flowable components by separating said flowable components from saidmixture, said apparatus comprising:a driven drum defining acircumferential surface; a pressure belt enclosing part of saidcircumferential surface and forming an entry wedge with said drum; atleast one pressure roller positioned so as to press said belt onto saidcircumferential surface; and supply means for supplying said mixtureinto said entry wedge; at least one non-perforated circumferential zonein said circumferential surface; at least one perforated circumferentialzone in said circumferential surface; said supply means includes meansfor feeding said mixture to at least an axially central region of saidat least one non-perforated circumferential zone; said drum has a shapeof a double cone, said double cone having a maximum diameter in an axialcentre of said at least on non-perforated circumferential region. 12.Apparatus for the processing of a material mixture containing flowableand non-flowable components by separating said flowable components fromsaid mixture, said apparatus comprising:a driven drum defining acircumferential surface; a pressure belt enclosing part of saidcircumferential surface and forming an entry wedge with said drum; atleast one pressure roller positioned so as to press said belt onto saidcircumferential surface; and supply means for supplying said mixtureinto said entry wedge; at least one non-perforated circumferential zonein said circumferential surface; at least one perforated circumferentialzone in said circumferential surface; said at least one non-perforatedcircumferential zone is axially centered in said drum; said at least oneperforated circumferential zone being at least first and secondperforated circumferential zones; said first perforated circumferentialzone being disposed adjacent a first edge of said at least onenon-perforated circumferential zone; and said second perforatedcircumferential zone being disposed adjacent a second opposed edge ofsaid at least one non-perforated circumferential zone; said pressurebelt covering at least one of said at least one non-perforatedcircumferential zone and said at least one perforated zone, and has athickness decreasing from an axial centre thereof toward its edges. saiddrum has a shape of a double cone, said double cone having a maximumdiameter in an axial centre of said at least on non-perforatedcircumferential region.
 13. Apparatus for the processing of a materialmixture containing flowable and non-flowable components by separatingsaid flowable components from said mixture, said apparatus comprising:adriven drum defining a circumferential surface; a pressure beltenclosing part of said circumferential surface and forming an entrywedge with said drum; at least one pressure roller positioned so as topress said belt onto said circumferential surface; and supply means forsupplying said mixture into said entry wedge; at least onenon-perforated circumferential zone in said circumferential surface; atleast one perforated circumferential zone in said circumferentialsurface; and said circumferential surface of said drum includes groovesin the region of said at least one non-perforated circumferential zone,said grooves extending substantially parallel to a longitudinal axis ofsaid perforated drum, and into said at least one perforated zone. 14.Apparatus as claimed in claim 13, further includes radial grooves atleast in a region between said at least one non-perforatedcircumferential zone and said at least one perforated zone. 15.Apparatus as claimed in claim 14, wherein said grooves substantiallyparallel to the longitudinal axis are deeper than said radial grooves.16. Apparatus for the processing of a material mixture containingflowable and non-flowable components by separating said flowablecomponents from said mixture, said apparatus comprising:a driven drumdefining a circumferential surface; a pressure belt enclosing part ofsaid circumferential surface and forming an entry wedge with said drum;at least one pressure roller positioned so as to press said belt ontosaid circumferential surface; and supply means for supplying saidmixture into said entry wedge; at least one non-perforatedcircumferential zone in said circumferential surface; at least oneperforated circumferential zone in said circumferential surface; saidsupply means includes means for feeding said mixture to at least anaxially central region of said at least one non-perforatedcircumferential zone; said circumferential surface of said drum includesgrooves in the region of said at least one non-perforatedcircumferential zone, said grooves extending substantially parallel to alongitudinal axis of said perforated drum, and into said at least oneperforated zone.
 17. Apparatus as claimed in claim 16, further includingradial grooves at least in a region between said at least onenon-perforated circumferential zone and said at least one perforatedzone.
 18. Apparatus for the processing of a material mixture containingflowable and non-flowable components by separating said flowablecomponents from said mixture, said apparatus comprising:a driven drumdefining a circumferential surface; a pressure belt enclosing part ofsaid circumferential surface and forming an entry wedge with said drum;at least one pressure roller positioned so as to press said belt ontosaid circumferential surface; and supply means for supplying saidmixture into said entry wedge; at least one non-perforatedcircumferential zone in said circumferential surface; at least oneperforated circumferential zone in said circumferential surface; said atleast one non-perforated circumferential zone is axially centered insaid drum; said at least one perforated circumferential zone being atleast first and second perforated circumferential zones; said firstperforated circumferential zone being disposed adjacent a first edge ofsaid at least one non-perforated circumferential zone; and said secondperforated circumferential zone being disposed adjacent a second opposededge of said at least one non-perforated circumferential zone; saidcircumferential surface of said drum includes grooves in the region ofsaid at least one non-perforated circumferential zone, said groovesextending substantially parallel to a longitudinal axis of saidperforated drum, and into said at least one perforated zone. 19.Apparatus as claimed in claim 18, further including radial grooves atleast in a region between said at least one non-perforatedcircumferential zone and said at least one perforated zone. 20.Apparatus as claimed in claim 19, wherein said grooves substantiallyparallel to the longitudinal axis are deeper than said radial grooves.